"I have put in my papers three to four days back and I am waiting for the new government to relieve me from the post," Rao told PTI.
Minister of State for Power, Coal and New & Renewable Energy Piyush Goyal assumed office yesterday. Prime Minister Narendra Modi and his 45-member council of ministers were sworn in on May 26.
Rao said if everything falls into place, he would take up a new role as principal secretary in the Telengana chief minister's office, "hopefully" from June 2.
Rao, a 1986 batch Andhra Pradesh cadre Indian Administrative Service (IAS) officer who hails from the Telangana region, was appointed chief of the world's largest coal producer in April 2012 for a five-year tenure. He is due to retire in 2018.
Before joining Coal India, Rao was CMD of Singareni Collieries Company Ltd, owned by the Andhra Pradesh government and the Government of India on a 51:49 equity basis.
The Telangana Rashtra Samithi is set to form the first government in Telengana, which will formally come into existence as the country's 29th state on June 2, following the bifurcation of Andhra Pradesh.